import {readdirSync, readFileSync} from 'fs'

const iconNames: string[] = []
const svgTitle = /<svg([^>+].*?)>/
const clearHeightWidth = /(width|height)="([^>+].*?)"/g
const hasViewBox = /(viewBox="[^>+].*?")/g
const clearReturn = /(\r)|(\n)/g
// 清理 svg 的 fill
const clearFill = /(fill="[^>+].*?")/g

function findSvgFile(dir: string, prefix: string): string[] {
	const svgRes = []
	const dirents = readdirSync(dir, {
		withFileTypes: true
	})
	for (const dirent of dirents) {
		iconNames.push(`${prefix}-${dirent.name.replace('.svg', '')}`)
		if (dirent.isDirectory()) {
			svgRes.push(...findSvgFile(dir + dirent.name + '/', prefix))
		} else {
			const svg = readFileSync(dir + dirent.name)
					.toString()
					.replace(clearReturn, '')
					.replace(clearFill, 'fill=""')
					.replace(svgTitle, ($1, $2) => {
						let width = 0
						let height = 0
						let content = $2.replace(clearHeightWidth, (s1: string, s2: string, s3: number) => {
							if (s2 === 'width') {
								width = s3
							} else if (s2 === 'height') {
								height = s3
							}
							return ''
						})
						if (!hasViewBox.test($2)) {
							content += `viewBox="0 0 ${width} ${height}"`
						}
						return `<symbol id="${prefix}-${dirent.name.replace('.svg', '')}" ${content}>`
					})
					.replace('</svg>', '</symbol>')
			svgRes.push(svg)
		}
	}
	return svgRes
}

export const svgUtil = (pathAndPrefixMap: Map<string, string>) => {
	if (!pathAndPrefixMap || pathAndPrefixMap.size === 0) {
		return
	}
	const result: string[] = []
	for (const entry of pathAndPrefixMap.entries()) {
		result.push(...findSvgFile(entry[0], entry[1]))
	}
	return {
		name: 'svg-transform',
		transformIndexHtml(html: string) {
			return html.replace(
					'<body>',
					`
          <body>
            <svg id="local-icon" data-icon-name="${iconNames.join(
							','
					)}" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" style="position: absolute; width: 0; height: 0">
              ${result.join('')}
            </svg>
          `
			)
		}
	}
}
